2145772123100 has 108 divisors (see below), whose sum is σ = 4916024026200. Its totient is φ = 812848417920.

The previous prime is 2145772123097. The next prime is 2145772123153. The reversal of 2145772123100 is 13212775412.

It is a super-2 number, since 2×2145772123100² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 122334131 + ... + 122351669.

Almost surely, 2^{2145772123100} is an apocalyptic number.

2145772123100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2145772123100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2458012013100).

2145772123100 is an abundant number, since it is smaller than the sum of its proper divisors (2770251903100).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2145772123100 is a wasteful number, since it uses less digits than its factorization.

2145772123100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20980 (or 20954 counting only the distinct ones).

The product of its (nonzero) digits is 23520, while the sum is 35.

Adding to 2145772123100 its reverse (13212775412), we get a palindrome (2158984898512).

The spelling of 2145772123100 in words is "two trillion, one hundred forty-five billion, seven hundred seventy-two million, one hundred twenty-three thousand, one hundred".